Martin v. Löwis <mar...@v.loewis.de> added the comment:
> Don't you think people ever referred to the type file directly? As in
> help(file)
Yes, certainly. There is no immediate replacement for that; read the io
documentation.
> dir(file)
Likewise
> file.somemethod(receiver, arg)?
No. Why would anybody want to do that?
> Or even storing a file method in a dictionary for dispatch?
Likewise: what's the use case? Are you sure people store unbound methods
in a dictionary? Why not bound methods?
> I claim they were quite ingrained in Python 2 user's minds.
Partially, perhaps. It's an unfortunate mistake that file ever became
a builtin - that should have been avoided (and py3k corrects it).
> In reviewing the "What's New" for the purpose of this reponse I noticed an
> earlier mention of sys.stdin, sys.stdout, and sys.stderr, where it says they
> are now instances of TextIOBase. (They are actually instances of
> TextIOWrapper,
> just like the result of open().)
Notice that sys.stdin/stdout/stderr are indeed instances of TextIOBase:
py> import sys,io
py> isinstance(sys.stdout, io.TextIOBase)
True
> So why can't the documentation of open() say
> that it returns an instance of TextIOBase too?
Because it would be incorrect to say so:
py> isinstance(open("/etc/passwd","rb"), io.TextIOBase)
False
> It just seems like a very wide trap to never mention that the whole file type
> is gone.
Well, Raymond promised to address this issue in his rewrite.
> OK, I didn't follow the technical details through and, as I said above, I
> hadn't
> noticed the earlier mention of TextIOBase for sys.stdout, etc. So just say
> something like "The type file is gone, replaced by classes in the IO module.
> Use open() to open a file."
That would be correct to say. We'll see what Raymond comes up with.
> And maybe add that it returns an instance of
> TextIOBase or TextIOWrapper, whichever is deemed more appropriate.
Neither. It would be correct to say that it returns an instance of
io.IOBase (which isn't really a class, but an ABC).
----------
title: "What's New" should say VERY CLEARLY that the type file is gone
-> "What's New" should say VERY CLEARLY that the type file is gone
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Python tracker <rep...@bugs.python.org>
<http://bugs.python.org/issue5513>
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